Method of making grating



July 19, 1932. J. MfKEOWN METHOD OF MAKING GRATING Filed Sept. 6, 1929 2 Sheets-Sheet l July 19, 1932. .1. M. KEOWN METHOD OF MAKING GRATING Filed Sept. 6, 1929 2 Sheets-Sheet 2 i 10 v & n

Patented July 19, 1932 UNITED STATES PATENT OFFICE JOHN M. KEOWN, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-FIFTH- TO ARTHUR E. SANGDAHL, OF WESTERN SPRINGS, ILLINOIS, ONE-FIFTH TO W. FORREST OGLE, OF CHICAGO, ILLINOIS, ONE-FIFTH T0 EDWIN J. LEARNED, OF LAKE FOREST, ILLINOIS, AND ONE-FIFTH TO BENTLEY F. RAMSDELL, 0F GENEVA, ILLINOIS METHOD OF MAKING GRATING Application filed September 8, 1929. Serial No. 890,704.

a method of making grating whereby the,

parts of the structure are permanently connected by forging operations.

Another, specific object is the provision of a method of making grating whereby the component parts of the gratin are so connected as to prevent rusting in t e oints and consequent loosening of the parts and weakening of the structure.

} Yet another specific object is the provision of a method of making grating, wherein, sim 1e commercial shapes may be employed in t e grating construction.

Another particular object of the invention is the provision of a method of making grating whereby the strength and stiffness of the component parts of the structure are maintained and utilized to the best advantage.

Other and further objects will be pointed out orindicated hereinafter, or will be apparent to one skilled in the art upon an understanding of the invention or its employment in practice.

In the following description and in the drawings forming part of this specification, the invention is explained through the disclosure of certain examples, but it is to be understood that these are presented for the purpose of illu tration merely, and are not to be construed in any fashion calculated to limit the appended claims short of the true and most comprehensive scope of'the invention in the art.

In said drawings,

- Fig. 1 is a diagram illustrating a schematic fashion various steps in the makin or forming of a grating;

ig. 2 is a top view of a section of a grating fabricated in conformity with the invention certain of the steps of the method also being illustrated thereon;

Fig. 3 is a. diagrammatic illustration on a somewhat larger scale illustrating an operation in theforming of a grating; i Fig. 4 is a perspective view of a portion of the completed grating; Fig. 5 is a section along the line 55 of Fig. 4; and

Fig. 6 is a section along the line 6-6 of Fig]. 4.

- ratings suitable for use as supporting surfaces, such as floor gratings, stair treads, walk ways, platforms, and the like, must possess the necessary strength and stifiness to support considerable loads, the stability or permanency of jointing or' connection of com-' ponent parts such as to prevent their becoming loosened under repeated pressure and permitting rattling and weaving, and theymust also lend themselves to pleasing and uniform design and to various dimensional require-. ments and accommodation of portions of building structure in association with which they are to be installed. Economical manufacture is of verydistinct importance, particularly as related to quantity reduction.

The present invention provides a method of manufacture of a grating'which satisfies these requirements in a very eftective'manner. It involves the use of only the simplest commercial rolled shapes of bars, and operations which may be performed automatically with rapidity and certainty. Described generally, the invention contemplates the proed through the punched openings in the carrier bars, the latter being arranged in parallel relationship at suitably spaced intervals. The net-work of bars being thus assembled, it is subjected to a. re-forming o ration whereby the portions of the connecting bars between the carrier bars are re-forined in such fashion that the bars arepermanently connected together, the ends of the connecting bars being upset upon theouter sides of the outermost carrier ars, and portions of the connecting bars being formed out flush tread side when it is installed for use.

' grain or fiber of the rolled metal is not broken,

nor, in punching the apertures in the carrier bars, is'the metal severed at either margin of vthe latter, and the crossed bars are firmly and intimately united. As a consequence, the

. strength and stiffness of the material is availed of to the best advantage and a stiff and rigid structure having moisture-proof joints is formed.

The invention will be understood more in detail by reference to the examples of operations and structure illustrated in the drawings. A suitable number of flat carrier bars 10, of steel or other suitable material, are punched at desired intervals to afford apertures 11 which are entirely between the margins of the bars, so that they are completely surrounded by the metal. The carrier bars being arranged in parallel collateral relationship, solid metal connecting bars 12, preferably of a cross-section which fits the apertures 11 with an easy sliding fit, are inserted through the aligned apertures of the carrier bars, the ends of theconnecting bars being projected slightly beyond the outermost carrier bars, as shown in portions of Fig. 2. The

network of bars being thus loosely assembled, it is fed through a heating furnace 14 wherein the connecting bars are heated to a temperature which will permit of their being readily forged. From the heating furnace the heated network of bars is fed intermittently to a forging apparatus, represented by the forging heads 15, and the-portions of the connecting bars between the carrier bars are reformed by pressures applied transversely to said portions. In'this re-forming operation the carrier bars are supported on a hard plane surfaced table 16 and some of the metal of the connecting bars is displaced beyond the upper and lower margins of the apertures 11 so that it overlaps opposite side portions of the carrier bars. and some of the metal is also forced longitudinally of the connecting bars so that the apertures 11 are completely and tightly filled, and fillets 17 are formed in the angles between the carrier bars and connecting bars. At the same time the projecting ends of the connecting bars are re-formed, as by the operation of suitable forging members 18, so as to head overthe ends of the connecting bars on the outer sides of the outermost carrier bars, forming the heads 12. During these re-forming operations, the carrier bars are held closely in contact with the table 16 by suitable holding-down pressure applied as by a member 19. In the re-forming of the connecting bars, portions of the metal thereof are pressed down closely into contact with the table surface, thus formin marglns on the connecting bars which are ush with the margins of the carrier bars which are in contact with the table surface. In Fig. 3 is with the table surface, it may be desirable to apply the forging pressures obliquely, so as to give the carrier bars a slightly tapering crosssection, approximately as illustrated. By use of suitable material for the connecting bars, and adequate pressure, it is apparent that this re-forming of the bars may be effected without the preliminary heating of them.

The re-forming of the connecting bars in the manner described effects a permanent connection of all ofthe bars in t e grating structure, producing a practicallyintegra-l fabric in which all of the bars are definitely held against shifting relative to one another.

The joints between the carrier bars and connecting bars, being formed by compression and swaging of the metal, are sufficiently close to prevent entrance of moisture. Hence, rusting in the joints is prevented, and the bars thus safeguarded against loosening in such fashion as to permit their rattling or to permit the structure weaving. During the intermittent feeding of the fabric to the forging operation, and during the reforming of the connecting ported and guided in the desired spacing and parallel relationship, which guidance and lateral support may be afforded, in part at least, by the forging heads, they being slotted to accommodate the carrier bars, and permit the feeding movement when the heads are in the retracted position, as illustrated in the dotted contour 15', wherein they clear the connecting bars but maintain lateral contact with the carrierbars. The forging membars, the carrier bars are sup-- bers which operate on opposite sides of a carrier bar are thus efiective to re-form simultaneously the portions of the connecting bar at opposite sides of the carrier bar.

The grating thus formed, which is illus-' trated in Figs. 4, 5 and 6, possesses very marked strength, stiffness and stability. The side of the grating which in the forging operation was in contact with the table. 16, constitutes the upper or tread surface of the finished structure. The stability of the structure results primarily from the closeness of the joints and the overlapping of the connecting bars on the sides of the carrier bars.

The strength and stillness are contributed,

in part by the fact that the integrity of the marginal portions of the carrier bars 1s maintained throughout their length, and the lon- 5 gitudinal fibre of the rolled connecting bars is not broken in the re-forming of them while they are heated. By virtue of the strength, stability and stiffness of the structure, gratings of this construction are well qualified for the supporting of heavy loads, such as may be imposed upon them in their use as floor gratings, latforms and the like, and because of the act that its joints are moistare-tight, it is particularly qualified for uses wherein it is exposed to the weather. The gra ing may be constructed, of course, with any desired spacing of the carrier bars and the connecting bars, and presents a regular and workmanlike design. The process is of great advantage in that it may be erformed rapidly and accurately, so that t e grating ity and at relatively low cost.

The invention in grating construction herein illustrated and described is claimed per se in my copending divisional application Serial No. 850,042, filed December 10, 1931.

What I claim is: r

' 1. A method of making grating which comprises arranging a plurality of transversely apertured carrier bars collaterally in a group, disposing connecting bars in said apertures in such fashion that each extends through a plurality of the carrier bars, advancing the assembled bars progressively in a direction longitudinally of the carrier bars, guiding the carrier bars in spaced relationshi to one another, and re-forming throug out their length the portions of the connecting bars between the carrier bars and forcing parts thereof into binding abutment with lateral surfaces of the carrier bars.

,2. A method of fabricating metallic grat ing which comprises providing a plurality of bars with transverse apertures entirely spaced from the bar margins, arranging said bars on edge in collateral spaced relationship, placing connector bars of solid cross section in the apertures in such fashion that each extends through a plurality of the first mentioned bars, transversely compressing the portions of said connector bars intermediate said first mentioned bars and thereby reforming said portions of the connector bars to change their cross-sectional form throughout their entire length and force part of their material into abutment'with lateral surfaces of the first'mentioned bars adjacent the apertures and compress part of the material of thy connector ars in the apertures to completelv fill the same.

3. A method of fabricating a atin which comprises providing a plur 'ty 0 bars with apertures entirely spaced from the bar margins, disposing said bars on edge in.

collateral spaced relationship with margins 4 tioned bars and displacing parts of said connector bar portions approximately'into the plane of the adjacent margins of the firstf mentioned bars.

4. A method of fabricating metallic grating which comprises providing a plurality of carrier bars each with a plurality of transverse apertures spaced apart longitudinally thereof, disposin said bars in collateral -s aced l t'onshl lac'n a luralit of may be produced in quantities with uniformp re a 1 p 1 g p y connector bars of solid metal cross section in the apertures in such fashion that each extends through a plurality of the carrier bars, and re-forming the portionsof the connector bars intermediate the carrier bars to change the cross sectional form of said portions throughout their entire length and bind the intersecting bar's together in fixed relative positions.

5. A method offabricating metallic grating as specified in claim 4 and wherein the portions of a connector bar on opposite sides of a carrier bar are re-formed simultaneously. i

.6. A method of fabricating metallic gratingas specified in claim 4 and wherein the said portions of the connector bars are re formed to reduce. their width andincrease their depth.

7. A method of fabricating metallic grating as specified in claim 4 and wherein the carrier bars are, held at definite spacing with respect to each other during the re-forming of the intervening portions of the connector bars, whereby to control the width of the grating apertures.

In testimony whereof I have hereunto subscribed my name.

JNO. M. K EOWN. 

